It is well known that fecal material is often difficult to remove from the skin of the user, in particular on sensitive skin such as by young babies and the skin around the genitals. Moreover, it is well known that fecal material on the skin can cause irritation and redness of the skin and some times even dermatitis of the skin.
One of the solutions to reduce the fecal material on the skin is to provide a means to isolate the fecal material immediately after discharge, away from the skin. The problem with feces isolation or in diapers is that the feces can vary hugely in consistency and viscosity and furthermore that, whilst isolating the feces, the diaper needs to retain its urine absorption capacity.
Hereto, diapers have been provided with a topsheet with one or more large openings, through which the feces can pass to a void space between the topsheet and the absorbent core. The fecal material is then stored underneath this topsheet, away from the skin.
As alternative, a diaper with a first topsheet with a multitude of small openings has been proposed, allowing low viscosity feces to pass through said openings onto the absorbent core, such that it may be isolated underneath said topsheet and such that the absorbent core may dewater the feces, such as for example taught in U.S. Pat. No. 5,342,338. Optionally, a second topsheet with openings may be present, which further allows immobilization of the feces and dewatering of the feces by the absorbent core underneath.
It has been found that improved feces isolation and immobilization and reduced re-soiling of the skin by the immobilized feces is achieved when the diaper comprises a topsheet with apertures of a specific size and a sublayer with holes of a specific size, which are positioned such that only a small degree of overlap between the holes and the apertures is present. The degree of overlap should be large enough to allow effective passage of feces through the apertures of the topsheet into the holes of the sublayer, but small enough to stop the feces in the holes of the sublayer from migrating back to the skin.
Furthermore, it has been found that the selection of the exact size (dimension) of the holes of the sublayer, at least in the plane of the surface facing the topsheet, are important to achieve effective isolation and immobilization of feces of varying viscosity (including dewatering thereof and storage thereof).
Thus, improved feces isolation, reduced rewet and improved feces immobilization are achieved with the diapers of the invention comprising the specific topsheet and sublayer described herein which have a small percentage overlap between the apertures of the topsheet and the holes of the sublayer.
Furthermore, it has been found that it is beneficial to provide a sublayer that is or comprises one or more acquisition layers that are furthermore pressure resistant even after wetting, to ensure the feces remains immobilized even after the sublayer has been wetted by liquid exudates and submitted to pressure.